ABSTRACT
Adaptation of crops to climate change has motivated an increasing interest in the potential value of novel traits from wild species; maize wild relatives, the teosintes, harbor traits that may be useful to maize breeding. To study the ecogeographic distribution of teosinte we constructed a robust database of 2363 teosinte occurrences from published sources for the period 1842-2016. A geographical information system integrating 216 environmental variables was created for Mexico and Central America and was used to characterize the environment of each teosinte occurrence site. The natural geographic distribution of teosinte extends from the Western Sierra Madre of the State of Chihuahua, Mexico to the Pacific coast of Nicaragua and Costa Rica, including practically the entire western part of Mesoamerica. The Mexican annuals Zea mays ssp. parviglumis and Zea mays ssp. mexicana show a wide distribution in Mexico, while Zea diploperennis, Zea luxurians, Zea perennis, Zea mays ssp. huehuetenangensis, Zea vespertilio and Zea nicaraguensis had more restricted and distinct ranges, representing less than 20% of the total occurrences. Only 11.2% of teosinte populations are found in Protected Natural Areas in Mexico and Central America. Ecogeographical analysis showed that teosinte can cope with extreme levels of precipitation and temperatures during growing season. Modelling teosinte geographic distribution demonstrated congruence between actual and potential distributions; however, some areas with no occurrences appear to be within the range of adaptation of teosintes. Field surveys should be prioritized to such regions to accelerate the discovery of unknown populations. Potential areas for teosintes Zea mays ssp. mexicana races Chalco, Nobogame, and Durango, Zea mays ssp. huehuetenangensis, Zea luxurians, Zea diploperennis and Zea nicaraguensis are geographically separated; however, partial overlapping occurs between Zea mays ssp. parviglumis and Zea perennis, between Zea mays ssp. parviglumis and Zea diploperennis, and between Zea mays ssp. mexicana race Chalco and Zea mays ssp. mexicana race Central Plateau. Assessing priority of collecting for conservation showed that permanent monitoring programs and in-situ conservation projects with participation of local farmer communities are critically needed; Zea mays ssp. mexicana (races Durango and Nobogame), Zea luxurians, Zea diploperennis, Zea perennis and Zea vespertilio should be considered as the highest priority taxa.
Subject(s)
Ecosystem , Geography , Zea mays/classification , Species SpecificityABSTRACT
In the reprint in this special issue of my 1974 paper, Are behavioral principles for revolutionaries?, I make thepoint that I remake in the article below: the definition of problem behavior and the contingencies affecting itschange are affected by the extent to which the individuals whose behavior is being targeted participate in thedefinition. Contingencies designed to impact human behavior can have deleterious effects if the impositionof these contingencies is on those without power or choice. When those in power enlist the expertise of behavioriststo change the behavior of those without power, our science tells us that the results will not be whatsome may expect. I conclude with lessons from the misapplications of behavior analysis in stratified powersystems that should affect our professional behavior to diminish the likelihood of additional misapplicationsof our science.(AU)
En la reedición en este número especial de mi artículo de 1974, ¿Servirán los principios conductuales paralos revolucionarios?, destaco un punto que ya estaba presente en este trabajo: la definición de los problemasde conducta y de las contingencias que afectan a su cambio se ven afectados por la medida en que los individuos,cuyo comportamiento está siendo cambiado, participan de la definición de lo problema. Contingenciasdiseñadas para impactar la conducta humana pueden tener efectos nocivos si estas contingencias se imponena los que no tienen poder o elección. Cuando los que están en el poder contan con la experiencia de los conductistaspara cambiar la conducta de los que no tienen poder, nuestra ciencia nos dice que los resultadosno serán lo que algunos pueden esperar. Concluyo con lecciones aprendidas de las malas aplicaciones delanálisis del comportamiento en los sistemas estratificados de poder que debería afectar nuestra conductaprofesional con el fin de reducir la posibilidad de malas aplicaciones de nuestra ciencia.(AU)
Na reedição, neste número especial, de meu artigo de 1974, Os princípios comportamentais servem para osrevolucionarios?, eu destaco um ponto que já estava presente neste texto: a definição de um comportamentoproblema e as contingências que influenciam sua mudança são afetadas pela extensão na qual os indivíduos,cujo comportamento é alvo de mudança, participam do próprio processo de definição do problema. Contingênciasplanejadas para impactar o comportamento humano podem ter efeitos deletérios se essas contingênciasforem impostas sobre aqueles sem poder ou escolha. Quando aqueles que estão no poder requisitam aexpertise dos comportamentalistas para mudar o comportamento daqueles desprovidos de poder, nossa ciêncianos diz que os resultados não serão aqueles que se deseja. Concluo com lições extraídas do mau uso daanálise do comportamento nos sistemas de poder estratificados, que deveriam afetar nosso comportamentoprofissional no sentido de diminuir a probabilidade de novos usos indevidos de nossa ciência.(AU)
Subject(s)
Behavior Therapy , Power, Psychological , Social ValuesABSTRACT
Na reedição, neste número especial, de meu artigo de 1974, Os princípios comportamentais servem para osrevolucionarios?, eu destaco um ponto que já estava presente neste texto: a definição de um comportamentoproblema e as contingências que influenciam sua mudança são afetadas pela extensão na qual os indivíduos,cujo comportamento é alvo de mudança, participam do próprio processo de definição do problema. Contingênciasplanejadas para impactar o comportamento humano podem ter efeitos deletérios se essas contingênciasforem impostas sobre aqueles sem poder ou escolha. Quando aqueles que estão no poder requisitam aexpertise dos comportamentalistas para mudar o comportamento daqueles desprovidos de poder, nossa ciêncianos diz que os resultados não serão aqueles que se deseja. Concluo com lições extraídas do mau uso daanálise do comportamento nos sistemas de poder estratificados, que deveriam afetar nosso comportamentoprofissional no sentido de diminuir a probabilidade de novos usos indevidos de nossa ciência.(AU)
In the reprint in this special issue of my 1974 paper, Are behavioral principles for revolutionaries?, I make thepoint that I remake in the article below: the definition of problem behavior and the contingencies affecting itschange are affected by the extent to which the individuals whose behavior is being targeted participate in thedefinition. Contingencies designed to impact human behavior can have deleterious effects if the impositionof these contingencies is on those without power or choice. When those in power enlist the expertise of behavioriststo change the behavior of those without power, our science tells us that the results will not be whatsome may expect. I conclude with lessons from the misapplications of behavior analysis in stratified powersystems that should affect our professional behavior to diminish the likelihood of additional misapplicationsof our science.(AU)
En la reedición en este número especial de mi artículo de 1974, ¿Servirán los principios conductuales paralos revolucionarios?, destaco un punto que ya estaba presente en este trabajo: la definición de los problemasde conducta y de las contingencias que afectan a su cambio se ven afectados por la medida en que los individuos,cuyo comportamiento está siendo cambiado, participan de la definición de lo problema. Contingenciasdiseñadas para impactar la conducta humana pueden tener efectos nocivos si estas contingencias se imponena los que no tienen poder o elección. Cuando los que están en el poder contan con la experiencia de los conductistaspara cambiar la conducta de los que no tienen poder, nuestra ciencia nos dice que los resultadosno serán lo que algunos pueden esperar. Concluyo con lecciones aprendidas de las malas aplicaciones delanálisis del comportamiento en los sistemas estratificados de poder que debería afectar nuestra conductaprofesional con el fin de reducir la posibilidad de malas aplicaciones de nuestra ciencia.(AU)
Subject(s)
Behavior Therapy , Power, Psychological , Social ValuesABSTRACT
Teosinte, the progenitor of maize, is restricted to tropical environments in Mexico and Central America. The pre-Columbian spread of maize from its center of origin in tropical Southern Mexico to the higher latitudes of the Americas required postdomestication selection for adaptation to longer day lengths. Flowering time of teosinte and tropical maize is delayed under long day lengths, whereas temperate maize evolved a reduced sensitivity to photoperiod. We measured flowering time of the maize nested association and diverse association mapping panels in the field under both short and long day lengths, and of a maize-teosinte mapping population under long day lengths. Flowering time in maize is a complex trait affected by many genes and the environment. Photoperiod response is one component of flowering time involving a subset of flowering time genes whose effects are strongly influenced by day length. Genome-wide association and targeted high-resolution linkage mapping identified ZmCCT, a homologue of the rice photoperiod response regulator Ghd7, as the most important gene affecting photoperiod response in maize. Under long day lengths ZmCCT alleles from diverse teosintes are consistently expressed at higher levels and confer later flowering than temperate maize alleles. Many maize inbred lines, including some adapted to tropical regions, carry ZmCCT alleles with no sensitivity to day length. Indigenous farmers of the Americas were remarkably successful at selecting on genetic variation at key genes affecting the photoperiod response to create maize varieties adapted to vastly diverse environments despite the hindrance of the geographic axis of the Americas and the complex genetic control of flowering time.
Subject(s)
Chromosome Mapping/methods , Plant Proteins/genetics , Repressor Proteins/genetics , Zea mays/genetics , Alleles , Chromosomes, Plant , Genes, Plant , Genetic Variation , Genome-Wide Association Study , Genotype , Haplotypes , Mexico , Models, Genetic , Phenotype , Photoperiod , Plant Proteins/metabolism , Quantitative Trait Loci , Repressor Proteins/metabolism , Time FactorsABSTRACT
In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from env positive tumor patients and in 3% (1/34) of the env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the genesis of this neoplasia and encourage the continuation of these studies.
Subject(s)
Breast Neoplasms/virology , Genes, env/genetics , Mammary Tumor Virus, Mouse/genetics , Animals , Argentina , Base Sequence , Female , Humans , Mice , Sequence HomologyABSTRACT
In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from env positive tumor patients and in 3% (1/34) of the env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the genesis of this neoplasia and encourage the continuation of these studies
Subject(s)
Humans , Animals , Female , Mice , Breast Neoplasms , Genes, env , Mammary Tumor Virus, Mouse , Retroviridae Infections , Tumor Virus Infections , Argentina , Base Sequence , Sequence HomologyABSTRACT
In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38
of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31
(23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17
(2/12) of the PBMC from env positive tumor patients and in 3
(1/34) of the env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the genesis of this neoplasia and encourage the continuation of these studies.
ABSTRACT
In the last years research on the possible viral etiology of human breast cancer has been revised. Previous studies have demonstrated the presence of a Mouse Mammary Tumor Virus (MMTV) env gene-like sequence in about 38% of breast cancers from American and Italian women; these sequences are generally absent in other tumors and in normal mammary tissue. In the present study we have analyzed the presence of a 250-bp sequence of the MMTV env gene in breast cancer biopsies from Argentine patients. The retroviral fragment was present in 31% (23/74) of the tumors, only in one normal mammary tissue and in none of the fibroadenomas analYzed. Peripheral blood mononuclear cells (PBMC) from 46 cancer patients were also analyzed; the sequence was found in 17% (2/12) of the PBMC from env positive tumor patients and in 3% (1/34) of the env negatives. The results from Argentine samples are similar to those from USA and Italy, where the breast cancer incidence is alike. These findings support the hypothesis of a viral agent involved in the genesis of this neoplasia and encourage the continuation of these studies (AU)
Subject(s)
Humans , Animals , Female , Mice , Genes, env , Mammary Tumor Virus, Mouse/genetics , Retroviridae Infections/genetics , Tumor Virus Infections/genetics , Breast Neoplasms/virology , Base Sequence , Sequence Homology , ArgentinaABSTRACT
The participation of viruses in mammary carcinogenesis has been largely studied in animals. A model similar to the mouse mammary tumor virus (MMTV) was previously proposed. Several lines of research supported the participation of MMTV in human breast cancer, but these evidences were contradicted when further research was performed. One major issue was the presence of human endogenous retroviral sequences that confounded results reporting MMTV-like sequences in human breast cancer. To overcome this problem we selected a 660 bp sequence of the MMTV env gene with low homology to endogenous sequences and search for a sequence to it using the polymerase chain reaction (PCR). The sequence was found in 38 of the human breast cancers and in 2 of the normal breasts studied. The sequence was not present in tumors from other organs. It was 90-98 homologous to MMTV and only 18 to human endogenous retrovirus (HERV) K-10. It was also detected in some of the positive tumors by Southern blot hybridization using one of the cloned 660 bp as a probe. Using reverse transcriptase PCR, it was possible to demonstrate that the 660 bp sequence is expressed in the majority of the tumors. Also, preliminary experiments revealed that sequences related to the LTR and gag genes of MMTV were present in the DNA of breast tumors. The origin of the MMTV-like sequences in tumor DNA could be the result of integrated MMTV-like sequences derived from a human mammary virus or may represent unknown endogenous sequences that can only be detected in breast tumors.
Subject(s)
Humans , Animals , Mice , Breast Neoplasms , Retroviridae Infections/genetics , Tumor Virus Infections/genetics , Mammary Neoplasms, Experimental/genetics , Mammary Tumor Virus, Mouse/genetics , Breast Neoplasms , Growth Substances/geneticsABSTRACT
The participation of viruses in mammary carcinogenesis has been largely studied in animals. A model similar to the mouse mammary tumor virus (MMTV) was previously proposed. Several lines of research supported the participation of MMTV in human breast cancer, but these evidences were contradicted when further research was performed. One major issue was the presence of human endogenous retroviral sequences that confounded results reporting MMTV-like sequences in human breast cancer. To overcome this problem we selected a 660 bp sequence of the MMTV env gene with low homology to endogenous sequences and search for a sequence to it using the polymerase chain reaction (PCR). The sequence was found in 38 of the human breast cancers and in 2 of the normal breasts studied. The sequence was not present in tumors from other organs. It was 90-98 homologous to MMTV and only 18 to human endogenous retrovirus (HERV) K-10. It was also detected in some of the positive tumors by Southern blot hybridization using one of the cloned 660 bp as a probe. Using reverse transcriptase PCR, it was possible to demonstrate that the 660 bp sequence is expressed in the majority of the tumors. Also, preliminary experiments revealed that sequences related to the LTR and gag genes of MMTV were present in the DNA of breast tumors. The origin of the MMTV-like sequences in tumor DNA could be the result of integrated MMTV-like sequences derived from a human mammary virus or may represent unknown endogenous sequences that can only be detected in breast tumors.(Au)
Subject(s)
Humans , Animals , Mice , Breast Neoplasms/virology , Mammary Neoplasms, Experimental/genetics , Mammary Tumor Virus, Mouse/genetics , Retroviridae Infections/genetics , Tumor Virus Infections/genetics , Breast Neoplasms/genetics , Growth Substances/geneticsSubject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Neoplasms/surgery , Neoplasms/drug therapy , Neoplasms/radiotherapy , Skin Neoplasms , Head and Neck Neoplasms , Breast Neoplasms , Prostatic Neoplasms , Bile Duct Neoplasms , Genital Neoplasms, Female , Genital Neoplasms, Male , Anus Neoplasms , Colonic Neoplasms , Esophageal Neoplasms , Stomach Neoplasms , Lung Neoplasms , Rectal Neoplasms , Central Nervous System Neoplasms , Pharyngeal Neoplasms , Urogenital Neoplasms , Liver NeoplasmsSubject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Neoplasms/surgery , Neoplasms/drug therapy , Neoplasms/radiotherapy , Skin Neoplasms , Head and Neck Neoplasms , Breast Neoplasms , Prostatic Neoplasms , Bile Duct Neoplasms , Genital Neoplasms, Female , Genital Neoplasms, Male , Anus Neoplasms , Colonic Neoplasms , Esophageal Neoplasms , Stomach Neoplasms , Lung Neoplasms , Rectal Neoplasms , Central Nervous System Neoplasms , Pharyngeal Neoplasms , Urogenital Neoplasms , Liver NeoplasmsABSTRACT
As características que os programas de modificação de comportamento frequentemente assumem são analisadas em termaos da ciência que lhes deu origem, o Comportamentalismo. Enquanto o Comportamentalismo assume que o comportamento é resultado de contingências e que mudanças duradouras no comportamento envolvem mudanças nas contingências que lhe dão origem e que o mantém, a maioria dos programas de modificação de comportamento simplesmente arranja contingências especiais, em um ambiente também especial, de forma a eliminar o comportamento problema. Mesmo quando o comportamento-problema ocorre de maneira tão generalizada, como o alcoolismo e a criminalidade, os modificadores de comportamento focalizam sua atenção no alcóolatra e no criminoso e não na modificação das contingências sociais que prevalecem fora do ambiente terapêutico e que continuam a produzir alcoólatras e criminosos. São analisadas também as contingências que modelam essa maneira de lidar com problemas comportamentais e estaanálise leva a uma crítica da estrutura social vigente em termos de um sistema de controle do comportamento. Embora os comportamentalistas que trabalham em áreas de aplicação se dediquem frequentemente a consertar indivíduos, a área da ciência denominada Comportamentalismo (Behaviorismo) fornece os meios para analisar as estruturas, o sistema e as formas de controle social que produzem os problemas(AU)